Beta-anthraquinone-carboxylic acids and the esters thereof and process of preparing them



w UNIT D- sT-m 1 1 CPI Patented Nov. 24, 1931 KARL WILKE, on FmxronT-oN-Tnnmaocnsr, GERMANY, assroiiron 'r-og'q u' 'nanr mnrnnwonxs mou on NEW YO BETA-ANTHRAQUINONE-CARBOXYLIG ACIDS Aim man Esme or PREPARING THEM melanom moon-Se NoDrawing. 'Applieationfiled J'u'neB, 1929, Serial. No. 369,016, and in Germany June 21, 1928.

The present invention relates to beta-anthraquinone-carboxylic acids and the esters thereof and to a process of reparing them.

I have found that by die influence of an alkali metal salt of hydrocyanic acid, betaanthraquinone-aldehydes are easily capable of combining additively with hydroxyl-containing compounds of the formula: R0H

wherein Rstands for hydrogen,- alkyl or aryl, as for instance water, alcohol or phenol. By 7 V this operation there a'r'e'obtained the-leuco compounds of. anthraquinone-carboxylic acids and the esters-thereof, respectively I Q. E o g in (lo/O @(Ii 8 g By oxidation of these intermediate vats, as

for instance by means of air, the corresponding anthraquinone derivatives are obtained with agoodyield. y 7 y Thereaction may already be effected by mixing the components'at' ordinary temperature, it being partially preferableto' heat the reaction mixture on-the water-bathi The anthraquinone-2 carboXyIic acidesters 7 thus obtained correspond to the following formula:

wherein R istandsfor allryl-or aryl and X for hydrogen, halogen or, an amino group,

generally forming faintly colored, -crystal-' of 10 parts of beta-anthraquinone-aldehyde to which 10'parts ofpotas'sium cyanide 'j(0r sodium cyanide) have sheen added, I, is

of the melting point of V i I eo' I The beta anthraquinone carboxylic acid V ethyl-ester is obtained inthe same manner,

when using ethyl alcohol instead ofmethyl I for the manufacture of dye-- thor'oughlystirred "at water-bath temperature and under free access of air until the first formed yellowish-red vat, has turned brownish-yellow; Thereup0n tli'e'inasslis filtered and the beta-anthraquinone-carboxylic acid precipitated from the filtrate by acidifying the latter with aceticacid, filtered by: suction, washedand driedg It has the follow" stitution: V i

and forms when recrystallized from glacial acetic ,acid a brownish' yellom:crystalline powder 287. C. V

(2) 3 parts of powdered potassium cyanide are introduced, while-well stirring, into a 'suspension pre pared fr m lO partsof beta-annx, N. Y.,'A ooRroRA'rIoN or thraquinone-aldehyde in IOOparts of methyl alcohol. Under self-evolution ofheat a deepred vat is immediately formed from which the methyl-ester of the beta-anthraquinone-j carboxylic acid of the following formula! O i p i c e OO-Q-QHa 1 i separate the action (sf-air. re-

as crystallization, from woodispirit the fprodutt i freed from small quantities lofjcfree car boxylic acid which simultaneouslyihavebeen formed, andobtained in th e ,formbf a pale; y llow crystalline powder havin'g its melting alcohol. solved from methyl alcohol $114730.

v(3) QOQparts of 1-iodo5anthraquinone-2- aldehyde (obtained by substituting in the 1-amino-anthraquinonek2 aldehyde, iodine The product melts when re -dis- :for the amino group, melting point 198 C. to

I V of-methyl alcohol untilthere can no '20,, o s r j a U 510 parts ofl-amino-anthraquinone-2- green yat 199 C.) aretreated in an open ball mill with 10 parts of potassium cyan'ide and 150 parts longer be observed any traces of a red Vat There uponthe mass is diluted-with water, filtered, washedwith a dilute solution of sodium carbonate and then with water-and dried. Aft er recrystallization irom alcohol, the resulting f1 i0 do anthraquinone- 2 -*carb acid methyl-ester melts between '17 2 C. and .175, 0., The product formsa bright, lightbrown," cryst'allinefpowder and has the following constitution:

* oh- I II I aldehyde are treated according to E zample3 with llosp s i potassium cyanidein bo t j 100 pans m yl alcohol until aitestsam ple taken from the reaction"mixture does no longer form with analkaline hydrosulfite solution a greeny-but ayellowish-red vat. Thereupon the :mass is diluted with water, oxidized, if necessary, by/"introducing 'air for a short -time, filtered, washed anddri'ed.

"The resulting 1-amino-'anthraquinone-2-carmethyl-ester crystallizes from boirylic acid I, 7 glacial acetic'acid in the form of red needles',

Hlulaz. i.

line hydro'sulfite. solution the characteristic pf; the aldehyde. 7 Thereupon the mixturefis" diluted] with water, filtered,"

one-'2-carboxylic acid phenyLester thuslobtained crystallizes from glacial aceticfacid formula stands for hydrogen, alkyl ora benzene resi mula Cfand has the following ior} r H washed and dried. The 1'-amino-,anthraquin-- in'the form of bright, reddish-golden 'crystals, melts at 198 and has the following 7 I V i I claim: i

'1; The process which comprises causing an anthraquinone-2aldehyde to act upon a compound of the formula: RYOH wherein R due in:the presence of analkali metal cya-. nide. r V Y 2.7 The process which comprises causing an anthr'aquinOne-Q aldehydeto act upon acomp' und of the formula R-O'H wherein- R standsvfor'hydrogen, alkyl or a benzene; res.- idue,'.flin1 the presence of 'potassium"'cyanide while heating on a water-bath.

3. The process which comprises causing an 7 "1 anthraquinone-2-ald h d. I the gene-r a1 formula stands hydrogen, "halogen or an amino group, the forniula R-V.OH wherein- R- stands for rhydrogenyalkyl or 'phenyl, in the presence v of an alkali metal cyanide; V c

4; The process which comprises causing an anthraquin one-Qaldehyde of the general for wherein X stands for hyuibgem h Q lOgen-or anamino g1fo up;,"to act upon a compound of the formulaifR ol-l wherein R stands for 7 hydrogen, alkyl or phenyl, in thepresence of V .potassiumcyanide while heating on a water-' f bath 7 V amino-anthraquinoneY-EZ-aldehyde to act upon methyl alcohol in presence of an alkali metal cyanide.

6. Theprocess which comprises causing 1- V amino-anthraquinOneQ aldehyde to act upon methyl alcohol in the presence of potassium V cyanide, while heating ona water bath.

' 7 As new products, compounds of the following general formula?" j V v residue, igeneral ly forming EaintlyY-colored V crys lline bodies. J: :xi

to act upon acompound of 8. As new products, compounds ofthe following general formula:

wherein R stands for alkyl or phenyl', generally forming faintly colored crystalline bodies.

9. As a new product, l-amino-anthraquinone-2-carboxylic acid methyl-ester being a 5 red crystalline powder andinelting at 228 C.

10. As a new product, l-amino-anthraquinone2-carboxylic acid phenyl-ester being a bright, reddish-golden crystalline powder and melting at 198 C.

In testimony whereof, I aflix my signature.

KARL WILKE. 

